Dave S.
Thanks for fixating on me. One more "Doug" rant, dedicated to trying to tear me down bit by bit from every direction your poor limited brain can think of.
I've had to ask myself if responding to each of your never-ending taunts is worth my time. I think the answer is "no". I'm going to try to stop responding to you since it is not productive.
I think you can see that the agencies you worship have also tired of your shizzle. You might notice a pattern here...
OK I think that is enough - for a lifetime!
Seeya!
:)
Doug Selsam

---

Joe:
You've done a great job, and nobody could ever replace you.
If this were a city council meeting, or a county planning commission meeting, you would be the mayor, or the county supervisor. The dude you're defending would be one of those whacked-out unemployed people who seldom bathe and show up to the meetings to make trouble and waste everyones' time.

I disagree that there is any reasonable AWE product out there. Anyone can craft a website and offer a promise of some dubious contraption that nobody has ever bought. And anyone can put a photo of a wheelbarrow on the web and claim it's the latest Indycar. So what?

You should take a clue from the growing list of people who are unwilling to even discuss anything with certain parties. And just posting a lot of crap doesn't change the fact that it's crap. How many proclamations that "thus and such will define the future of AWE" have we suffered through by now - every week the proclamation changes. I don't know about you but I've had lots of years of experience to identify who is a player and who is an obnoxious nutcase in wind energy.

Also who is a liar: There's no field so full of lies as wind energy - look at the "superior" Honeywell machine - a big joke. How 'bout Aerovironment: no longer promoted after the big lies of economical power production, and the supposed effectiveness of this product unraveled, exactly as the veterans identified at first glance. But of course wind energy veterans are the LAST people the nutcases ever want to have to deal with!

Liars change their story a lot - it keeps everyone guessing. A lie could be "I understand this art" or a lie could be "This sort of array will define the future of airborne wind energy", then it never does. Why would anyone want to keep listening to what can logically only be a string of lies, since every successive statement contradicts the previous one?

Wind energy in general brings the nuts out of the woodwork, but AWE TAKES THE CAKE! The less factual and accurate among them seek to endlessly shift the discussion to a personality contest, try to claim they are persecuted, that everyone is against them etc. This has not changed in 10 years, and can quickly become a self-fulfilling prophecy, and I take you back to the city council meeting analogy - nobody wants to deal with "that nutcase" - they just wish he would pipe down, stop interrupting the meeting, stop trying to control the discussion, go away, and find someplace to bathe.

I'm not sure of what is a good way to say this, but sometimes the company we keep can hurt us. Others associate a group of people with whomever is most vocal among them, most harmful, or even just most obnoxious, on the "birds of a feather flock together" theory. You can see, in real time, it impacting your own credibility and it looks like if you don't see the writing on the wall soon, you could easily end up going from the top dog in AWE to someone whom nobody in AWE will even talk to, simply on the basis of guilt by association.

Wish things weren't this way, but they've been this way for all 10 years of my involvement with wind energy. I've searched for why wind energy is this way - drawing so many nutcases - and my answer is, it's because the wind is invisible, so for people who know nothing of wind energy, everything is "up for discussion", nothing is "known", there is no baseline of facts to deal with, no history, and basically, no facts.

Invisible wind - make up any facts you like and who can deny them? Then you add in the fact that the next 2 steps: magnetism and electricity are also both invisible, and you have machines combining 3 invisible forces. Hence the nutcases. If you were talking about a fence, everyone can touch it and see it, so you don't see a lot of emotional nutcase debates about a fence. Fences don't bring 100 nutcases out of the woodwork with new theories of fencebuilding. That's because fences are not invisible, not mysterious.

Newbies in wind energy always want to throw out the veterans' opinions and substitute their own wishes for facts, but in the end, Mother Nature has the final say. So far she agrees with us veterans, as to who knows, and who is just one more nut!
:)
Doug S.

---

Dave,

Practical AWE does not depend upon consensus it depends upon getting the
science and the engineering and the economics right. All of those
considerations make jet-stream AWE a waste of time - always. It is
really easy to come up with numerous ideas. It is really hard to develop
real viable products. The art of product development is to eliminate
many thousands of possibilities and concentrate on the easiest route to
success. Jet streams, LTA of any sort and pure fly-gen should all be
eliminated from future consideration for good hard scientific reasons.
Science is the study of God's rules and they change for no man.

Robert.

Dave,

Maybe our definitions of 'AWE' are at odds. My definition excludes pure
transport applications. Yes, jet streams already do have applications
for transport and I am in no way pessimistic about future transport
uses. I am saying that AWE for energy generation needs to start at low
altitudes and then slowly move higher as the need demands.

Many dreamers have a poor understanding of science so they waste time on
impractical ideas. To let conversations based on faulty science run on
does no one any favours.

Robert.

George Lawrence did some impossibles. 

On Sat, 2011-12-17 at 16:40 -0800, dave santos wrote:
Dave,

For many years I lived on the slopes of Table Mountain. It is famous for
its table cloth. Often you can watch clouds form as the air goes up one
side and disappear again as it goes down the other side. It is big
enough to cause a weak rain shadow. The idea that it would be practical
to build an AWE system big enough to do the same is to me a joke. You
need to raise air about 1000 m to make enough difference and an AWE
system 1000 m high would be composed of many parts so it would cause
mixing but not precipitation.

But actually the message I am trying to convey is that we all need to be
vigilant and watch that we ourselves, and others, are not allowed to get
away with saying things that are provably wrong. The truth always wins
so the sooner it is revealed the better.

Robert.

A debate between the Carnegie Institution and Max Planck Institute
should be required to know what are real possibilities for HAWE.

"At heights of 7 to 16 kilometres, the air in jet streams moves at
constant speeds of over 25 metres per second or 90 kilometres an
hour.""However, their speed is due to the near absence of friction and
not to strong propulsion"

7 to 16 kilometers are a huge part of HAWE,and morever are its head.And
it is not expected that wind energy under 7 km is higher (before we
considered it as lower).Morever higher is the tapped altitude,higher
could be the climate change,that from 0 to 7 km as well as above (but in
a lesser proportion).Some questions:what is the real potential of the
whole wind energy?What should be the optimal altitudes for AWES?

So the major argument in favour of the AWES with regard to wind towers
should be its lightness and its moderate cost more than its faculty in
tapper winds in high altitude.

So the conjunction of bottlenecks in high altitude,supplement of
tether,rules of aviation,could favor harnessing winds at low altitude (0
to 500 ft,perhaps 1200 ft but not more).

PierreB

Many forums develop a resident bully. The bully is an elder male who
knows enough to stand his ground in all arguments that arise and has the
time to have the last word on every topic. He corrects all mistaken
statements on the forum but creates antagonism by being stubborn and
rigid in his views. He justifies his status by contributing large
volumes of useful content but often alienates people who make valid
comments but are coming from a different perspective. He can redeem
himself by concentrating more on quality than quantity. Dave, you are
the AWE bully.

To answer the points you make, I must say I thought searching for
mountains associated with Cambridge was amusing. It is boringly flat for
many miles in all directions. To be clear what I am talking about the
bottom picture shows the table cloth effect most clearly.
http://www.wayfaring.info/2009/09/15/table-mountain/

The rain shadow effect only happens when the weather is borderline and
is caused by a structure about 1000m high and 5000m wide. When the rain
comes from the North west everywhere gets wet. Borderline humid air from
the South east drops rain on the eastern slopes while protected bays on
the western side (eg. Camps bay) are sunny.

The Hawaiian islands have the most pronounced rain shadow of anywhere I
have visited. The mountains are higher and the prevailing wind is more
dominant.

As air goes up the side of a mountain the pressure drops. When the
pressure drops the temperature drops - about 6.5 C per 1000 m. If the
dew point of the incoming air happens to be above the temperature
reached at the top of the mountain then clouds and rain can form.

To change the subject briefly, this phenomena of gas temperature
changing with pressure is the reason why using compressed air to
transmit energy from a wind generator is another idea with no prospects.
To bring the process efficiency up to a useful level huge heat
exchangers are needed to keep the temperature reasonably stable.

My objective is to get an AWE device on the market asap. I am not here
for science fiction debates. There is absolutely no danger of any AWE
device I could build in the next decade having any measurable rain
shadow effect. If in the 20's AWE is booming and our kites get as big as
mountains we can revisit the discussion but for now I see it as a time
wasting irrelevance.

Robert.

BTW, just a reminder, on this list there are sufficient Dave's to
warrant using our list-approved (;-)) appellation convention, namely,

Dave = Dave Culp (the default Dave by historical precedence)

DaveS = Dave Santos

DaveL = Dave Lang

and any other Dave(s) can follow this established protocol.

I make this reminder since the occasional level of acrimony often
makes me cringe when I see a response attacking a "Dave" (for fear it
is I who might have offended, OR, conversely, if I offended, then I
haven't received full-credit for same :-)).

thanks

DaveL

Pierre, 

Earthbound wind turbines show clear economies of scale.  The size available to a lone experimenter is functional, but uneconomic.  It seems likely that AWE will start with small kites and low altitudes, and then push those limits, just as aviation still does.  Our challenge seems to be to get over the hump to a scale that can compete with other wind turbines.  Our easiest niche is probably remote locations, where the costs of delivery and installation give us an advantage.

Apologies for not being totally clear about which Dave I was addressing.
I value the discussions we have here so I might get carried away a bit
sometimes trying to press for quicker progress. 2012 is promising to be
a very challenging year so I think it is important to focus on getting
some large-scale AWE happening asap.

The key to this rain shadow effect is the 6.5 C per 1000 m figure. If
you know how high the air is raised you can estimate the temperature
drop. If you know the relative humidity of the incoming air you can
estimate how high you need to go before saturation (dew point) is
reached. It is complicated by the fact that most of the rain comes from
air well above the ground. You need something mountain sized to lift a
huge volume of air from which rain can be squeezed. The tendency to
super-saturate also complicates calculations. So I still think it is a
non-issue for AWE.

Robert.

NLP phrasing for proposals:

Joe,

Roughly 12 fabric kites of 500 m² could compete with a single 5 MW towered three-blade machine.One side something like 30 tons of materials + 1/10 part of concrete;other side 400 tons + concrete.But kites and tethers must be replaced every year or 6 months. When (fabric) kites and tethers will be 2 or 3 more resistant AWES will can compete with towers offshore.

PierreB  

Hey Robert
Just because you can't think of a way to stratospheric AWE it right now, doesn't mean it can't be done, and certainly not that nobody should discuss it. I don't think AWE will turn out to seem so complicated or mysterious once it is working.
Doug S.

Robert:
OK here's something you said that is wrong: You said an AWE system would push air down so it won't cause precipitation. You think somehow science is on your side, since aerodynamic lift to elevate the system would push air downward. But since you don't know that a wind energy system blocks most of the air otherwise going thru it, by 2/3 at the betz coefficient, most air goes around, not thru a wind turbine. And a lot of that could easily be pushed up and have to go over some sort of giant AWE array. So if you said one thing that could be wrong, and you were convinced that it was proven science, how many other things you say and try to push on others are wrong? Maybe lots of them. I think you're over-reaching in trying to say so far ahead of the fact what is possible or what people should consider, though I do agree that sticking with the facts is a good idea too.
:)
Doug Selsam

A detail to fit in the discussion: 

DaveS,

"Did Peter Lynn's recent finding of far longer kite life not convince you? Six months service life is only about what 1980's kites normally had, but there is a lot of progress since then! Unless the great Peter Lynn is mistaken, UV-block urethane-sized polyester (like Goo SkySilk) should give a few years of service life."

"Unless the great Peter Lynn is mistaken":no,Peter Lynn's kites are probably better:10 000 hrs is already good for ROI of AWES,and much more than 1000 hrs generally admitted for paragliders.Now it is interesting to see how are conditions:crosswind?Pilot-kite?

PierreB

Joe:
I'd ignore all these overly-self-important wannabe AWE entities, and their opinions. Sure someday AWE will be defending itself against environmental interests who will cite slowed winds and come up with a thousand ways it could affect the climate, etc. Most likely they'll decide that wind energy thereby clogs one of Earth's primary heat exchange mechanisms (winds) and it will be taxed on that basis.

I don't see how you could compare a hypothetical system that is so unknown that a working prototype does not exist (no known workable, survivable structure), with a proven design that you can walk up to and "kick the tires" of. I say, why keep such a debate "on paper", by citing a 5 mW turbine, which represents the latest working size of regular wind energy? At such a large size, any AWE system must necessarily be only hypothetical, since nobody is building one that big yet, so the comparison cannot be fact-based so much as projection-based (fantasy-based), and the projections could be wrong.

Why not target, say, a 10 kW turbine on a 120-foot tower such as that which powers our place, and compare a working 10 AWE kW system that operates at 120 feet or below? That would seem more achievable and would be an real apples-to-apples comparison. At that size and height, a real working system could be developed for comparison with existing, real, working systems. The main item of interest for ANY wind energy system is, "is it still there today?". most new systems simply can't survive even the first decent windy day!

Real wind energy systems are rated by 1) Hopefully they can make the nameplate power. 2) Is it still there the next day? Most new systems fail test 1, and if they pass test 1, will generally fail test 2. Any "professor crackpot" can compare his hypothetical system with any real system and come out ahead, since professor C. can ascribe any operating characteristics to his fantasy machine that he deems necessary to outperform what actually is.
:)
Doug S.

-

It's not the scale that is the problem. The problem is not knowing what to build at any scale. Regular wind energy sells more small turbines than large. In fact sales by unit numbers sold are inversely proportional to turbine size. The small turbines are economical in their niche, just as large ones are. People who need the power will pay what it takes to get that power, where they need it, when they need it. The idea that one cannot develop a working AWE system unless it is at the megawatt scale is just an excuse - an artifact of having nothing to offer at any scale, so an excuse of scale sounds better than "we don't know how to do it".

Doug, I was not proposing starting at megawatts.  I'm not surprised that there are more small turbines being sold than large ones, but their contribution to the energy supply is smaller, partly because they are farther into the boundary layer, which is less of a problem with kites.  I recommended going after the same market that uses their small turbines for power, not just "green" lawn sculpture.  Kites are tension structures, so they also scale up easily.

In a large kite array, there may be an advantage to furling some kites in stronger winds, to keep the forces and power more constant.  This action might be triggered by spars which bend in use, up to the force that causes them to fail.  If the failure mode is like the buckling of an over-extended tape measure, it causes no damage, and lets the structure pop open again when loads are reduced.  Tree leaves are notable for being inflated structures (by sap) which collapse to a low-drag form under high aero loads.  The tricky bit is probably to avoid flapping.

Since we are best advised to deal only in tension structures...
Furling may be best achieved by tension difference control, ...
decreasing the gap of the C shape of inflated ram air parafoils, kites or paragliders.

In the case of my spinning kite set; Having a more elastic tether on the outer tethers of the kites set on the ring.

As wind increases, the extra stretch on the outer lines makes the outer extent of the kite tip fold back and central to the axis of rotation.

A similarly more elastic back than front line promotes automatic sheeting out.

So as the wind increases the amount of sail presented to the wind decreases and the angle of attack lessens.

A self limiting power set-up is really quite simple and elegant.

Now if you want to totally kill and bring down the stack... Force the generator which normally points downwind at the stack to rotate off the wind. This will make the rotating kites snake and whip around, jerk, skew, slow their rotation and crash... probably.. I'm willing to try it.

And if you think that's ridiculous...
You should see the design I have for one of those funny wave power clams using underwater kites.


roddyIP

OK sorry to suggest you start with a system under 10 kW. What's the nameplate power capacity of the system are you building?

--- In AirborneWindEnergy@yahoogroups.com, Bob Stuart <bobstuart@...

Roderick:
Let me tell you from experience: these contests WASTE YOUR TIME. They WASTE YOUR ENERGY. They are judged by IDIOTS. You will NOT WIN. If you do it will LEAD TO NOTHING. Check into how much total time was wasted by America's up-and-coming inventors to jump through the GE Ecomagination hoops. What was the result? Has anything changed from wasting all that effort? Any of the promises come true? How many billions were supposed to go toward developing the proferred ideas? All that spiritual energy? How 'bout ARPA-E - can you point to any solutions they've generated? Show me a positive result for anyone from any of these contests or agencies. Show me one real solution.

You can do AWE, if only you realize that these are all people who can't do anything, which is why they have contests instead. It's all just bureaucratic fun for them. Like they are in high school, no results are ever expected, they are just "going for a grade" defined by who can waste taxpayer and investor money in the sexiest way, using the best clean energy lies.

--- In AirborneWindEnergy@yahoogroups.com, "roderickjosephread" <rod.read@... *** hey maybe that can be another official self-sabotaging, not-seeing-the-forest-for-the-trees "rule"! Combine everyone's stated "rules", just the ones I've heard so far, and you would be unable to construct ANYTHING. ***

*********************
*** Sure, try it and see how centrifugal force plays in...
Of course if you don't plan on anything spinning fast, it won't matter, but fast rotation has proven to be the best way... Oh nevermind I feel myself falling into the realm of wasted words - I know, I know, experience NOT required, not desired...
*********************
**************
****Blah blah blah blah blah simple da blabitty-blah-elegant-de blibitty-blah - Sure til you build it and see all the problems - then it breaks***
**************

*****************
*** I was responding to another post that suggested such an apples-to-apples comparison at tower height. OK Dave S. take it up to 500 feet with my blessing and show us your apples-to-apples 10 kW comparison. Sure, all you need is a few more feet of kiteline. Or make it a 1 kW comparison, at any height you like. Or any height your heroes-of-the-week will let you work at, this week, or next week, depending on their bureaucratic mood, hopefully not entirely based on how much you piss them off by being so obnoxious. ****
- Doug S.
PS I wish you would forget how to string the letters D-- O-- U-- and G together.
PSS come here during a storm, so we're getting the full 10-12 kW on the meter of the real wind turbines, and tell me about a few feet of kiteline (yell loud so we can hear you over the wind, rain, and turbines) while you're chasing your kite rig across the open desert at 50 mph.

News Release,
December 20, 2011

hello Joe

SeaGlider is truly amazing. Good call.

After I had dropped out of UCI as a physics major, seeing no curiosity or urge to try anything new at the university, I found myself at a community college learning CAD so I could prepare patents on my simple ideas that the university professors had scratched their heads at while showing no interest.

My first drawing was a boat pulled by a kite. My thought was that the next step wpould be to leave the keel down in the water on a tether, and the boat would then be airborne. I thought "Soon a new class of yachts will emerge, where the boat is in the air". This was before the first kitesurfer.

I lived in Huntington Beach, CA (surf city) and was surfing a lot then, and wondered why windsurfers weren't using kites. Why hold up the sail when it can hold itself up? Hello, you got wind, right? Ever heard of a kite? hello!!!
I've always thought the same thing about wind energy. You got wind, right? What;s with the tower? Hello!!! A tower for a wind turbine is only an intermediate step, like a mast for a windsurfer.
I think the most amazing thing about airborne wind energy is that nobody is doing it! OK gotta go skiing now! Catch some air! Seeya!

Doug Selsam